"Belgrano's data unit"
Good question. I was only giving an e.g. of how Aviation's memory is preserved. The "Belgrano" is the offices of the UK's Safety Regulator, the CAA. Rather too well known to UK pilots, engineers, ATCOs and so on.
The data unit within it keeps all sorts of records of Aviation "incidents" around the world. As the UK operates a crude "freedom of information" regime, the info. held can be made available to Brit.s. The "Belgrano" tag comes from its looks - a hulk of a battleship-grey office block near LGW.